The present invention relates to an image forming apparatus having a flash light fixing apparatus.
One type of image forming apparatus is configured to form a latent image on a surface of a photosensitive drum, transfers toner on that latent image to paper and fix that toner to said paper.
The portion that performs the fixing in the image forming apparatus described above has a fixing apparatus incorporated to it.
One type of fixing apparatus is a flash light fixing apparatus that irradiates flash light and fixes it.
In this flash light fixing apparatus, the temperature of the surface in the member that guides the paper can have its temperature raised easily because of the irradiated flush light.
When the temperature of the paper guide surface rises to above a predetermined temperature, various types of problems that will be described later, occur so that it is necessary for the paper guide mechanism to have a structure whereby the temperature does not rise easily.
FIG. 1 shows an outline configuration of one example of a conventional image forming apparatus 10. The numeral 11 represents a photosensitive drum, and 12 represents a flash light fixing apparatus 12.
The flash light fixing apparatus 12 comprises a flash light fixing unit 13 and a paper feed apparatus 14 provided to the lower side of the flash light fixing unit 13.
The paper feed apparatus 14 comprises a paper feed mechanism 15 comprising suction rotating rollers and a plural number of paper guide apparatus 16 that smoothly guide the fed paper above them.
The paper guide apparatus 16 has a configuration whereby a plural number of long, thin guide plates 17 with a width W1 of about 40 mm are arranged parallel to each other in the direction of paper feed indicated by the arrow 18.
The paper 19 to which the toner on the latent image formed on the surface of the photosensitive drum 11 has been transferred is fed by the paper feed mechanism 15 and is fed through inside the flash light fixing apparatus 12, in a state of being guided by the paper guide apparatus 16. While it is being fed, a flash light is irradiated from the flash light fixing unit 13 to fix the image.
When there is to be printing on both sides of the paper, the paper 19a that is sent from the flash light fixing apparatus 12 is fed in the direction shown by the arrow 20. The rear surface of the paper 19a is in contact with the photosensitive drum 11 and toner is transferred to the rear surface and then the paper passes through the flash light fixing apparatus 12 and the toner is fixed to the rear of the paper 19a.
Flash light is irradiated to the paper guide apparatus 16 and the temperature of the guide surfaces 17a of the guide plates 17 rises.
The following problems occur when the temperature of the guide surfaces 17a of the guide plates 17 rises.
(1) Of the actions to perform printing on both sides, when there is the process to fix the image on the rear side of the paper, the toner on the front side (lower side) adheres to the guide surfaces 17a of the guide plates 17. This adhered toner adheres to the paper that is fed next and dirties the paper and causes the print quality to deteriorate.
(2) There is the danger of the fingers of the operator being burnt when there is operation to remove misfed paper from the flash light fixing apparatus 12.